Navy’s Rail Gun Blasts Through Budget Restrictions

The Navy came very, very close to losing its futuristic gun that shoots bullets with a giant electric charge. But while a congressional committee recommended axing the Electromagnetic Railgun in June, the program survived — even if it’s still got to clear lots of technical hurdles before it can launch bullets from ships at hypersonic speed. And it’s not the only high-tech Navy project that looks like it (mostly) dodged the budget axe.

After years of testing a lab model at the Navy surface warfare center in Dahlgren, Virginia, the railgun — a gun without moving parts that fires a round through a big burst of electricity — is finally moving into a prototype phase. Next week, BAE System’s version of the railgun should arrive at Dahlgren for tests, followed in April by General Atomics’ version.

Meanwhile, Raytheon is developing the central nervous system of the railgun — the battery package that stores and then blasts the energy to send a bullet through the barrel. A shipboard demonstration should be ready, tentatively, by 2019.

But that was before the railgun’s powerful friends on the Hill fought back. “The other three committees [overseeing the military] decided the program was worth continuing,” reflects Nevin Carr, a retired two-star admiral who stepped down in the fall from running the futuristic Office of Naval Research. The railgun might still get its funding reduced when the defense budget is released on Monday. But the budget bill that emerged in December let the project live — so long as the Navy gives Congress a report answering more detailed questions more often about the railgun program.

“Democracy is a conversation,” says Carr, a railgun die-hard.

Except the committee’s concerns weren’t exactly baseless. Gun barrels typically wear out after releasing 500 to 600 rounds. But it’s unclear how a barrel that pushes energy through holds up. Carr says that the Navy has fired “over 100 rounds” through a test barrel so far.

But there are at least three other big technical challenges ahead for the railgun.

First, the gun is supposed to sit aboard an Arleigh Burke-class Destroyer. But different destroyers, at different ages, generate different amounts of power — or, more precisely, react differently when diverting generator power to, say, a railgun. Carr says that generating more than 26 megajoules for a shot — which should send a bullet careening across hundreds of miles of ocean in mere minutes — shouldn’t be a problem, but railgun tests are already running at 33 megajoules. “You may have to add additional power” to the ship, Carr says. That costs money.

Second, the railgun currently fires a dumb old lump of metal. And the military is three decades deep into smart, electronically enhanced munitions, to minimize civilian casualties. But a hypersonic electric burst is going to burn electronics to a melty mess of metal. Carr says that in a “couple of years” the Navy will “coalesce” a variety of immature efforts to build temperature-resistant guidance systems for the railgun’s bullet.

Finally, there’s the repetition rate — how many shots the railgun can fire how quickly. You can’t exactly put an electric gun on automatic. The Navy wants the railgun to fire six to 10 rounds a minute, but it’s not clear yet that the gun can do that. “One [round] a minute, that’s less useful,” Carr says.

But it’s looking more like the seafarers have largely protected their high-tech priorities from the austerity-minded Congress — even if some of those systems might get a fiscal shave and a haircut. That, at least, was Greenert’s message when Danger Room briefly interviewed him on Saturday aboard the U.S.S. Wasp.